Method of producing light weight aggregates from breaker waste and the like



F 1933; c. E. ZOOPER ET AL. 1,896,884

METHOD OF PRODUCING LIGHT WEIGHT AGGREGATES FROM BREAKER WASTE AND THE LIKE Filed NOV. 6, 1931 Even fora." ghienc'p E. (be Der,-

Patented Feb. 7, 1933 UNITED STATES PATENT OFFICE CLARENCE E. COOPER AND- HENRY S. GILBERTSON, OF LANSFORD, PENNSYLVANIA,

ASSIGNORS TO LEHIGH NAVIGATION COAL COMPANY, OF LANSFORD, PENNSYL- VANIA, A CORPORATION OF PENNSYLVANIA METHOD, OF PRODUCING LIGHT WEIGHT AGGREGATES FROM BREAKER WASTE AND THE LIKE Application filed November 6, 1931. Serial No. 573,507.

This invention relates to an improved meth- 0d of manufacturing light weight cellular products suitable for use as aggregates in concrete, and to an apparatus for use in carrying out such methods.

An important object of the invention is the production of an aggregate of this type from waste materials of coalbreakers, washeries of mine refuse banks or-other source of materials which in common with those derived from the sources specifically mentioned contain a' small percentage of carbonaceous fuel.

A further object of the invention is the provision of an apparatus for and a method of handling'such materials which permits of a rapid burning of a layer of this material of considerable thickness, therebyenabling rapid and economical production of the aggregate and at the same time producing a stronger and harder substance than when the charge is burned slowly.

A still further object of the invention is to provide in an apparatus of this character an arrangement such that waste heat may be readily utilized.

These and other objects we attain by the construction shown in the accompanying drawing wherein the figure is a diagrammatic showing of a furnace for carrying out the aggregate burning in accordance with our invention.

Referring now more particularly to the drawing, the numeral 10 generally designates a moving grate which is preferably, as illustrated, of the endless'type. Arranged above this grate are primary and secondary combustion chambers 11 and 12 and fuel feeding devices 13 and 14. Combustion chamber 11 preferably includes a relatively low arch and is in communication with the adjacent end of combustion chamber 12 through a duct 15. Combustion chamber 12 has a relatively long flat arch constructed to promote the movement of gases and products of combustion from what is therear end of the combustion chamber, as regards the direction of movement of grate 10, to'the forward end of this arch and thus through the duct 15. Cc1nbus tion chamber 11 is provided with an outlet 16 for the products of combustion. and the combustion chamber 12 is similarly provided as indicated at 17. In the present instance, the outlet 16 of combustion chamber 11 is illustrated as being directed into the outlet 17 of the combustion chamber 12 preferably at a point above a damper 18 separating the outlet 17 from the combustion chamber 12. Beneath the grate, in alignment with combustion chamber 11, a low pressure wind box '19 is disposed and beneath the forward end ignited at its upper surface by heat radiated from the heated arch of chamber 11 and is acted upon by low pressure windto promote combustion of the relatively thin layer L of material thus laid down. The desired thickness of layer L may be had by regulation of an adjustable feed-controlling device 22 or the like. Passing from beneath the combustion chamber 11 and arriving beneath the fuel-feeding device 14, a second layer L is laid over the layer L completing the bed B. Obviously, the material of layer L, since it is placed upon the burning layer L, will immediately begin to burn at its under surface. Arriving beneath the combustion chamber 12, it is ignited at its upper surface by heatradiated from arch of chamber 12 by reason of the fact that the products ofcombustion in this chamber are sweeping thereover in their passage to the combustion chamber 11 so that the completed bed B is now burning air and during its passage over the low pres- I sure wind-box 20 combustion spreads through the entire layer. T he completely ignited bed then passes over the high pressure wind box 21 with the result that it is-caused' to complete its burning very rapidly toexhaust the 2 I 1,see,es4?

carbonaceous material therein and is finally cooled to a certain extent by the air from the high pressure wind box 21 before it passes from beneath the arch in the form of a cake 5 or solid which may be broken into the desired sizes and employed as an aggregate in concrete work.

Employing this method in treating break- 1 or waste and the like, it has been found possible to produce high grade aggregates from waste containing as high as 70 percent ash.- The rapid burning resulting from the ignition of the bed at a multiplicity of points in the depth thereof insures a harder, stronger substance than it is possible to produce by the slower burning methods heretofore employed. It will be obvious that while .two combustion chambers" have been illustrated and the material has been shown and dcscribed as deposited in two layers, the principle liereinbefore set forth might be extended to increase the number of layers in the completed bed. By reason of the fact that the burning operation is very .rapid, apparatus in accordance with this invention readily lends itselfto use in combination with heatexchange apparatus such as a boiler radiator or the like. 1

It will be obvious that since this process provides for rapid burning of the carbona ceous content of the material through ignition of the bed at a plurality of points in its depth the ash content of the material may be much higher than that of 7 materials employed in similar processes. Where the ash content of the material is too high foreficient burning thereof, it may be reduced by iutermingling the same with other waste material having a lower ash content or a low 40 grade coal. To start operation of the furnace and to maintain combustion under some circumstances burners 11-a may be employed in the combustion chamber 11 to ignite the layer L.

. Since both the method and apparatus are capable of a certain range of change and modification without in any manner depart.- ing from the spirit of our invention, we do not wish to be understoodas limiting ourselves thereto except as hereinafter claimed.

We claim: The method of producing light weight aggregates by burning carbonaceous material having a high ash content consisting in forms ing a bed of successive layers, igniting the upper surface of each layer and after-application of the final layer conducting the products of combustion of the bed over the bed to initiate and promote combustion of the upper surface of the final layer of the bed and over the upper surface of a previously laid layer of the bed to initiate and promote combustion thereof.

a. CLARENCE E. COOPER.

HENRY s. GILBERT'SON. 

